Both arguments are correct. There is both ice debris and UFOs, but they get mixed up in this clip. That is because all of them looks the same in this camera. You can see the other video (https://youtu.be/OC7zw8aemlg) where they do a formation.

Here is some hints how to distinguish them.

Not affected as much in size as the ice debris when zooming inn/out, since they are further away.

They got sharper edge and are more dense (although less visible many times because of the distance).

Can appear from nowhere even though no zooming.

Faraway objects, they cover a large distance in a short time even when zoomed out (indication of high speed) and some almost leave a trail behind, while the close debris passes camera view only by floating and no trail.